Where was the radiator leaking from? If it was the cap a new one will help keep pressure and help with cooling. If it was a hose perhaps a lower pressure cap because the one in there holds more pressure than the rest of your cooling system should. Or new rad hoses if they were leaking and are older

As for the trans, I believe thats still cooled by the radiator, so if you fix that problem, the trans should follow. Still best to get rid of that burnt fluid though.

Some have installed trans coolers, I see them around 100 bucks. You could try that but is more of a bandaid fix without solving the real problem